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SavannaSavanna is grassland with scattered individual trees. Savannas of one sort or another cover almost half the surface of Africa (about five million square miles, generally central Africa) and large areas of Australia, South America, and India. Climate is the most important factor in creating a savanna. Savannas are always found in warm or hot climates where the annual rainfall is from about 50.8 to 127 cm (20-50 inches) per year. It is crucial that the rainfall is concentrated in six or eight months of the year, followed by a long period of drought when fires can occur. If the rain were well distributed throughout the year, many such areas would become tropical forest. Savannas which result from climatic conditions are called climatic savannas. Savannas that are caused by soil conditions and that are not entirely maintained by fire are called edaphic savannas. These can occur on hills or ridges where the soil is shallow, or in valleys where clay soils become waterlogged in wet weather. A third type of savanna, known as derived savanna, is the result of people clearing forest land for cultivation. Farmers fell a tract of forest, burn the dead trees, and plant crops in the ashes for as long as the soil remains fertile. Then, the field is abandoned and, although forest trees may recolonize, grass takes over on the bare ground (succession), becoming luxuriant enough to burn within a year or so. In Africa, a heavy concentration of elephants in protected parkland have created a savanna by eating leaves and twigs and breaking off the branches, smashing the trunks and stripping the bark of trees. Elephants can convert a dense woodland into an open grassland in a short period of time. Annual fires then maintain the area as a savanna.

Highly adaptable, tigers range from the Siberian taiga, to open grasslands, to tropical mangrove swamps. They are territorial and generally solitary animals, often requiring large contiguous areas of habitat that support their prey demands. This, coupled with the fact that they are endemic to some of the more densely populated places on earth, has caused significant conflicts with humans. Of the nine subspecies of modern tiger, three are extinct and the remaining six are classified as endangered, some critically so. The primary direct causes are habitat destruction and fragmentation, and hunting. Their historical range, which once reached from Mesopotamia and the Caucasus through most of South and East Asia, has been radically reduced. While all surviving species are under formal protection, poaching, habitat destruction and inbreeding depression continue to be threats.

Tigers are perhaps the most recognisable of all the cats (with the possible exception of the lion). They typically have rusty-reddish to brown-rusty coats, a whitish medial and ventral area, a white "fringe" that surrounds the face, and stripes that vary from brown or gray to pure black.

Main article: Golden tabby A rare golden tabby/strawberry tiger at the Buffalo Zoo. In addition, another recessive gene may create a very unusual "golden tabby" colour variation, sometimes known as "strawberry." Golden tabby tigers have light gold fur, pale legs and faint orange stripes. Their fur tends to be much thicker than normal.[50] There are extremely few golden tabby tigers in captivity, around 30 in all. Like white tigers, strawberry tigers are invariably at least part Bengal. Some golden tabby tigers, called heterozygous tigers, carry the white tiger gene, and when two such tigers are mated, can produce some stripeless white offspring. Both white and golden tabby tigers tend to be larger than average Bengal tigers.

The four major types of biomes are aquatic, grasslands, forests, and desert. Aquatic biomes are probably the most important of all the biomes. Their medium, water, is a major natural resource. Aquatic biomes can be subdivided into freshwater, seawater and atmospheric biomes. Grasslands can be subdivided into savanna, temperate grasslands (prairie) and tundra. This classification corresponds to decreasing average temperatures. Forests receive more precipitation than other biomes and vary from boreal, to temperate, to rainforest. This classification corresponds to increasing temperatures. Deserts have the fewest species and the most extreme climate

Slash and burn consists of cutting and burning of forests or woodlands to create fields for agriculture or pasture for livestock, or for a variety of other purposes. It is sometimes part of shifting cultivation agriculture, and of transhumance livestock herding. Historically, the practice of slash and burn has been widely practiced throughout most of the world, in grasslands as well as woodlands, and known by many names. In temperate regions, such as Europe and North America, the practice has been mostly abandoned over the past few centuries. Today the term is mainly associated with tropical rain forests. Slash and burn techniques are used by between 200 and 500 million people worldwide.[1] Older English terms for slash and burn include assarting, swidden, and fire-fallow cultivation. Slash and burn is a specific functional element of certain farming practices, often shifting cultivation systems. In some cases such as parts of Madagascar, slash and burn may have no cyclical aspects (e.g., some slash and burn activities can render soils incapable of further yields for generations), or may be practiced on its own as a single cycle farming activity with no follow on cropping cycle. Shifting cultivation normally implies the existence of a cropping cycle component, whereas slash-and-burn actions may or may not be followed by cropping.

Biomes are the major regional groupings of plants and animals discernible at a global scale. Their distribution patterns are strongly correlated with regional climate patterns and identified according to the climax vegetation type. However, a biome is composed not only of the climax vegetation, but also of associated successional communities, persistent subclimax communities, fauna, and soils.

The global distribution pattern: Where each biome is found and how each varies geographically. A given biome may be composed of different taxa on different continents. Continent-specific associations of species within a given biome are known as formations and often are known by different local names. For example,the temperate grassland biome is variously called prairie, steppe, pampa, or veld, depending on where it occurs (North America, Eurasia, South America, and southern Africa, respectively). The general characteristics of the regional climate and the limitations or requirements imposed upon life by specific temperature and/or precipitation patterns. Aspects of the physical environment that may exert a stronger influence than climate in determining common plant growthforms and/or subclimax vegetation. Usually these factors are conditions of the substrate (e.g., waterlogged; excessively droughty, nutrient-poor) or of disturbance (e.g., periodic flooding or burning). The soil order(s) that characterize the biome and those processes involved in soil development. The dominant, characteristic, and unique growthforms; vertical stratification; leaf shape, size, and habit; and special adaptations of the vegetation. Examples of the last are peculiar life histories or reproductive strategies, dispersal mechanisms, root structure, and so forth. The types of animals (especially vertebrates) characteristic of the biome and their typical morphological, physiological, and/or behavioral adaptations to the environment.

The global distribution pattern: Where each biome is found and how each varies geographically. A given biome may be composed of different taxa on different continents. Continent-specific associations of species within a given biome are known as formations and often are known by different local names. For example,the temperate grassland biome is variously called prairie, steppe, pampa, or veld, depending on where it occurs (North America, Eurasia, South America, and southern Africa, respectively). The general characteristics of the regional climate and the limitations or requirements imposed upon life by specific temperature and/or precipitation patterns. Aspects of the physical environment that may exert a stronger influence than climate in determining common plant growthforms and/or subclimax vegetation. Usually these factors are conditions of the substrate (e.g., waterlogged; excessively droughty, nutrient-poor) or of disturbance (e.g., periodic flooding or burning). The soil order(s) that characterize the biome and those processes involved in soil development. The dominant, characteristic, and unique growthforms; vertical stratification; leaf shape, size, and habit; and special adaptations of the vegetation. Examples of the last are peculiar life histories or reproductive strategies, dispersal mechanisms, root structure, and so forth. The types of animals (especially vertebrates) characteristic of the biome and their typical morphological, physiological, and/or behavioral adaptations to the environment.

A biome is a large geographical area of distinctive plant and animal groups, which are adapted to that particular environment. The climate and geography of a region determines what type of biome can exist in that region. Major biomes include deserts, forests, grasslands, tundra, and several types of aquatic environments. Each biome consists of many ecosystems whose communities have adapted to the small differences in climate and the environment inside the biome. All living things are closely related to their environment. Any change in one part of an environment, like an increase or decrease of a species of animal or plant, causes a ripple effect of change in through other parts of the environment. The earth includes a huge variety of living things, from complex plants and animals to very simple, one-celled organisms. But large or small, simple or complex, no organism lives alone. Each depends in some way on other living and nonliving things in its surroundings.

A biome is an area on the earth's surface that has a certain set of characteristics. There are seven kinds of biomes in the world: tundra, taiga, temperate forest, tropical rainforest, desert, grassland, and ocean. The map above shows where each of these biomes can be found around the world. Although it does not appear in the key, the ocean is represented by the blue area on the map.

Cold, snowy, windy. When you hear those words they make you think of mountains. The Alpine biome is like winter is to people in New England; snow, high winds, ice, all the typical winter things. In Latin the word for 'high mountain' is 'alpes'. That is where today's word alpine comes from. Alpine biomes are found in the mountain regions all around the world. They are usually at an altitude of about 10,000 feet or more. The Alpine biome lies just below the snow line of a mountain. As you go up a mountain, you will travel through many biomes. In the North American Rocky Mountains you begin in a desert biome. As you climb you go through a deciduous forest biome, grassland biome, steppe biome, and taiga biome before you reach the cold Alpine biome. In the summer average temperatures range from 10 to 15° C . In the winter the temperatures are below freezing. The winter season can last from October to May. The summer season may last from June to September. The temperatures in the Alpine biome can also change from warm to freezing in one day. Because the severe climate of the Alpine biome, plants and animals have developed adaptations to those conditions. There are only about 200 species of Alpine plants. At high altitudes there is very little CO2, which plants need to carry on photosynthesis. Because of the cold and wind, most plants are small perennial groundcover plants which grow and reproduce slowly. They protect themselves from the cold and wind by hugging the ground. Taller plants or trees would soon get blown over and freeze. When plants die they don't decompose very quickly because of the cold. This makes for poor soil conditions. Most Alpine plants can grow in sandy and rocky soil. Plants have also adapted to the dry conditions of the Alpine biome. Plant books and catalogs warn you about over watering Alpine plants. Alpine animals have to deal with two types of problems: the cold and too much high UV wavelengths. This is because there is less atmosphere to filter UV rays from the sun. There are only warm blooded animals in the Alpine biome, although there are insects. Alpine animals adapt to the cold by hibernating, migrating to lower, warmer areas, or insulating their bodies with layers of fat. Animals will also tend to have shorter legs, tails, and ears, in order to reduce heat loss. Alpine animals also have larger lungs, more blood cells and hemoglobin because of the increase of pressure and lack of oxygen at higher altitudes. This is also true for people who have lived on mountains for a long time, like the Indians of the Andes Mountains in South America and the Sherpas of the Himalayas in Asia. bibliography: "Himalayas", http://encarta.msn.com/find/, (June 2000). "General Ecology, EEOB 404", http://www.tulane.edu/~eeob/Courses/Ecology_Materials/arctic_alpine_99f.html, (June 2000).